The ALC231 headphone amplifier can drive a 32Ω headphone load without external DC blocking capacitors, eliminating pop noise caused by these capacitors. In addition to the cap-free headphone output port (HP-OUT), the LINE-OUT port is also designed as a line-level output without the need for DC blocking capacitors, eliminating pop noise when connecting to external powered speakers.

The integrated mono Class-D amplifier directly drives a mini speaker with as low as 4Ω impedance. Its maximum output power is 2 Watts at 5V power supply. The built-in high-pass filter with configurable cut-off frequency can prevent speaker burn up caused by low-frequency sound. The Class-D amplifier output power can also be limited to prevent mini speaker damage.

The ALC231 has overcurrent and short circuit detection to protect the integrated Class-D amplifier and power system. The Class-D amplifier output will be automatically shut down when a connected speaker is disconnected or to prevent over-heating. As well as protection functions, the ALC231 features spread spectrum and slew rate control for the Class-D carrier frequency to reduce EMI radiation.

Support for 16/20/24-bit SPDIF output with up to 192kHz sample rate offers easy connection of PCs to consumer electronic products, or transport of digital audio output to a High Definition Media Interface (HDMI) transmitter.